1. Field of the Invention
The present invention relates generally to arrangements for sorting vehicle bodies by the colors of coating expected thereon in a vehicle body coating line, and more particularly, is directed to an arrangement provided in a vehicle body coating line for storing temporarily vehicle bodies therein and supplying successively the vehicle bodies temporarily stored to a coating process in the vehicle body coating line in such a manner that the vehicle bodies are sorted in dependence on the colors of coating expected thereon.
2. Description of the Prior Art
In an automobile production plant, uncolored vehicle bodies obtained from a body assembly line are transported successively to a vehicle body coating line including a undercoating process and second and final coating processes to be coated therein, and each of coated vehicle bodies obtained from the vehicle body coating line is further transported to a vehicle assembly line in which the coated vehicle body is provided with various parts or appliances. There has been proposed a vehicle body production system in which a plurality of vehicle bodies of various types, grades or colors are supplied to a common vehicle body coating line to be provided with respective coatings. In such a system, the manner of supplying the vehicle bodies to the vehicle body coating line is so controlled that work amount at each of working stages provided in the vehicle body assembly line is well-balanced, in consideration of the types and grades of the vehicle bodies. Since the vehicle bodies supplied to the vehicle body coating line are to be provided with respective coatings of different colors, a change of color in a coating process provided in the vehicle body coating line is carried out in such a manner that a worker detects color of coating expected on each of the vehicle bodies conveyed thereinto and makes arrangements for supplying a selected paint corresponding to detected color to a paint spraying device provided for coating the vehicle bodies from one of paint tanks, which contains the selected paint, as disclosed in, for example, the Japanese patent application published before examination under publication number 54-72243.
In the previously proposed vehicle body production system as mentioned above, however, since the vehicle bodies are supplied to the vehicle body coating line without consideration of the colors of coating expected on the vehicle bodies, it is required to carry out frequently the change of color in the coating process provided in the vehicle body coating line, and such frequent changes of color in the coating process bring about waste of paints and increase of work amount in the coating process, so that the productivity of vehicle bodies is reduced. Further, the frequent changes of color at the stage of coating process result in a disadvantage that, in case of two successive coating operations by which vehicle bodies are coated in respective different colors, mist of paint produced in the preceding coating operation is apt to have a harmful influence upon the following coating operation and therefore the coating of the vehicle body colored by the following coating operation is deteriorated in color quality.